After upgrading to 2048 bit key and SHA256 signature certificates, the certificates of non-root users become obsolete and must be deleted in order to allow non-root users to log in. Perform the following steps to delete the non-root certificates for each non-root user:
# rm -rf /user_home_directory/.VRTSat
# hauser -add <user name> -priv <Privilege>
# /opt/VRTS/bin/halogin <non_root_user> <password>